Device for attaching bulldozer blades

ABSTRACT

A MOUNTING ASSEMBLY FOR TILTABLE BULLDOZER BLADES INCLUDING LATERAL BLADE LOAD RESISTING STRUTS AND MEANS FOR CONNECTING THE STRUTS TO THE REAR OF THE BULLDOZER BLADE IN A WAY SUCH THAT INTERNAL STRESSING OF THE BLADE FOR TILTING PURPOSES IS IN NO WAY IMPEDED BY THE STRUT MOUNTING ASSEMBLY. VARIOUS EMBODIEMENTS ARE DICLOSED THOUGH IN EACH INSTANCE A PAIR OF BRACE MEMBERS ARE PIVOTALLY MOUNTED IN GENERALLY END TO END RELATION ON THE REAR OF THE BLADE, THE INNER ENDS OF THE BRACE MEMBERS BEING YEILDINGLY INTERCONNECTED SO AS TO INHIBIT STRESS TRANSFER BETWEEN THE BRACE MEMBERS.

March 1973 YASUSHI MARUI 19 DEVICE FOR ATTACHING BULLDOZER BLADES Original Filed Feb. 26, 1970 4 Sheets-Shed l INVENTOR YASUSHI MARUI A ORNEYS March 6, 1973 YASUSHI MARUI 3,719,235

DEVICE FOR AITACHING BULLDOZE'R BLADES Original Filed Feb. 26, 1970 4 Sheets-Sheet 2 Fig.4

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34 I6 I? 33 I6 35 INVENTOR YASUSHI MARUI Aws March 6, 1973 YASUSHI MARUI 3,719,235

DEVICE FOR ATTACHING BULLDOZER BLADES Original Filed Feb. 26, 1970 4 Sheets-Sheet 5 INVENTOR YASUSHI MARUI 3% A ORNEYS March 6, 1973 YASUSHI MARUI 3,719,235

DEVICE FOR ATTACHING BULLDQZER BLADES Original Filed Feb. 26, 1970 4 Sheets-Sheet 4 l I r l8 34 39303735 A INVENTOR YASUSHI MARUI 8% W :ms

United States Patent O 3,719,235 DEVICE FOR ATTACHING BULLDOZER BLADES Yasushi Marni, Tokyo, Japan, assignor to Kabushiki Kaisha Komatsu Seisakusho, Tokyo, Japan Original application Feb. 26, 1970, Ser. No. 14,440. Divided and this application Nov. 22, 1971, Ser. No. 200,925 Claims priority, application Japan, Mar. 4, 1969, 44/ 15,885 Int. Cl. E02f 3/76 US. Cl. 172-803 2 Claims ABSTRACT OF THE DISCLOSURE A mounting assembly for tiltable bulldozer blades including lateral blade load resisting struts and means for connecting the struts to the rear of the bulldozer blade in a way such that internal stressing of the blade for tilting purposes is in no way'impeded by the strut mounting assembly. Various embodiments are disclosed though in each instance a pair of brace members are pivotally mounted in generally end to end relation on the rear of the blade, the inner ends of the brace members being yieldably interconnected so as to inhibit stress transfer between the brace members.

BACKGROUND OF THE INVENTION This is a division, of application Ser. No. 14,440, now abandoned, filed Feb. 26, 1970.

This invention relates to bulldozers of the type in which the dozer blade is tiltable about a longitudinal axis parallel to the direction of blade travel in operation, and more particularly it concerns a blade mounting arrange ment for such tilting dozer blades by which blade stresses incurred as a result of normal operations are fully accounted for without in any way interfering with tilting movement of the blade.

In tilting blade bulldozers of the type to which the present invention relates, tilting movement of the blade about a longitudinal axis is achieved by an extensible arm or strut in the form of a ram and cylinder extending between the main blade support arm pivotally connected at the lower rear side at one end of the blade, and the upper edge at the same end of the blade. The opposite end of the blade is similarly supported top and bottom but by a linkage assembly by which fore and aft pivotal movement at that end of the blade is prevented. Hence, operation of the adjustable linkage to pivot the upper edge at the one end of the blade forwardly, will raise that end of the blade relative to the other to bring about the intended tilting movement. correspondingly, flexing the blade so as to pivot the upper portion thereof at the one end rearwardly relative to the other end will lower the one end of the blade relative to the other to effect tilting in an opposite direction.

To resist lateral loads imposed on the blade during operation, struts are conventionally provided between a bracket fixed centrally of the blade and the two main mounting arms serving to establish the principal connection of the blade to the dozer body or other unit on which the blade ordinarily would be mounted. While such struts have proven satisfactory in the past to stabilize the blade against lateral loading, the tilting movement of the blade has imposed severe stresses in the struts or their mounts and have led to various problems including breakage of or damage to the blade mounting structure.

SUM-MARY OF THE PRESENT INVENTION In accordance with the present invention, the problems heretofore experienced with blade mounts for tiltable bulldozers are substantially overcome by a connection of 3,719,235 Patented Mar. 6, 1973 "ice the struts resisting lateral external loads imposed on the blades during operation, to the central rear portion of the blade, which connection isolates the transition of stresses between the respective lateral load resisting struts in such a manner that the aforementioned tilting movement can take place without imposing stress on the struts. In a basic sense, the connection employs a relatively rotatable telescopic link so that forces tending to stress the strut extending to one side of the blade are not imposed on the strut extending to the other side hereof. Various specific forms or embodiments of this basic strut connecting structure are contemplated by the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of one embodiment of a tilting bulldozer blade mounting assembly in accordance with this invention;

FIG. 2 is a rear perspective view of the assembly shown in FIG. 1;

FIG. 3 is an enlarged fragmentary plan view of a subassembly by which lateral load resisting struts are attached to the back of the dozer blade;

FIG. 4 is a rear elevation of the sub-assembly shown in FIG. 3;

FIG. 5 is a fragmentary plan view of an alternative embodiment of the sub-assembly shown in FIGS. 3 and 4;

FIG. 6 is a rear elevation of the sub-assembly shown in FIG. 5;

FIG. 7 is a fragmentary plan view of a further alternative embodiment of the sub-assembly shown in FIG. 3;

FIG. 8 is a fragmentary plan view of still a further embodiment of the sub-assembly shown in FIG. 3;

FIG. 9 is a rear elevation of the sub-assembly shown in FIG. 8; and

FIG. 10 is a plan view illustrating a conventional mounting assembly for tiltable bulldozer blades of the type to which the present invention relates.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS To facilitate a clear understanding of the present invention and its relation to prior art devices, reference is first made to FIG. 10 of the drawing which illustrates the general organization of the conventional tilting dozer blade mounting assemblies. Although the improved mounting assembly of the present invention is depicted in FIGS. 1-9 of the drawings, like reference numerals are used in the drawings to designate corresponding components. Hence the ensusing discussion of the prior art with reference to FIG. 10 of the drawings will also apply in some measure to FIGS. 1 and 2 thereof.

As shown in FIG. 10, in the conventional tilting blade bulldozer, the blade 2 is attached to the front end portions of side frames 3 and 4 through pin or ball-joint brackets 5 and the rear end portions of the side frames 3 and 4 are each attached to a trunnion 6 fixed on the side of the bulldozer body 1. Pivotal movement of the blade 2 about the axis of the pins 5 is restricted by arms 7 and 8 connecting the upper portions of the right and left sides of the rear surface of the blade 2 to the upper surfaces of the side frames 3 and 4, the arms 7 and 8 being connected to the blade through a ball-joint, for example, and to the side frames 3 and 4 by pin brackets 9. To achieve blade tiltability about a longitudinal axis extending parallel to the direction of blade operation, either one of the right and left arms 7 and 8 is extensible whereas the other is of fixed length. Specifically, in the embodiment illustrated in FIG. 10, the right arm 7 (the one facing the front of the blade 2) is of fixed length whereas the left arm 8 is extensible by virtue of a conventional oil pressure actuated cylinder 10 operated under the control of an appropriate hydraulic valve (not shown). By virtue of this arrangement, and in accordance with conventional practice, extension of the arm 8 to effect a forward pivotal movement of the left upper end of the blade will raise that end relative to the right end of the blade whereas a rearward tilting movement effected by contraction of the arm 8 will lower the left end of the blade relative to the right end thereof.

To stabilize the blade mounting assembly against lateral loads imposed on the blades during operation, right and left struts 13 and 14, respectively, are provided in accordance with conventional practice for connection between a double pin bracket 11 fixed on the central rear surface portion of the blade 2 and pin brackets 12 on the internal surfaces of the side frames 3 and 4.

As aforementioned, during operation of the bulldozer to tilt the blade 2 to the right or the left, the angle between the blade 2 and the side frame 4 is changed at one end of the blade. In conventional mounting assemblies of the type depicted by FIG. 10 of the drawings, however, the connection of the struts 13 and 14 between the blade 2 and the side frames 3 and 4 is in opposition to such angular changes. Hence the struts 13 as well as the side frames 3 and 4 are unnecessarily stressed in achieving the intended tilting movement of the blade 2 and has, in the past, resulted in damage through bending or breaking of these components.

In accordance with the present invention, the problems resulting from the imposition of unnecessary stresses in the components 3, 4, 13 and 14 as well as in the blade 2 are overcome without in any way sacrificing the lateral resistance and stability to external loads on the blade 2. As a result, the operating life of tiltable dozer blades mounting assemblies of the present invention is materially extended.

In FIGS. 1-4 of the drawings, one embodiment of a center brace structure, generally designated by the reference numeral 22, is shown to include a flex plate bracket 33 fixed centrally to the rear portion of the blade 2 and carrying a pair of brace members 34 and 35 pivotally though non-rotatably secured to the bracket plate 33 by pins 16. The outboard ends of the braces 34 and 35 are connected by ball-joints 18 to the inner ends of lateral stabilizing struts 19 and 20, in turn connected at their outer ends by pin brackets 21 to the side frames 3 and 4. The inner ends of the braces 34 and 35 are telescopically received within a sleeve member 17 in such a way as to be relatively rotatable and slidable with respect to each other and to the sleeve 17. As a result of this construction, there can be no stress transmission between the two pins 16 mounting the braces 34 and 35 to the bracket 33 and hence no interference with blade flexing by the hydraulic cylinder 10 to effect the tilting movement of the blade in the manner described above.

In the alternative embodiment shown in FIGS. and 6 of the drawings, the braces 34 and 35, again pivoted by pin 16 to the bracket 33 as in the previous embodiment, are formed with offset ends 24 and 25 connected by an intermediate link 26 with vertically disposed pins 27 and 28. Hence, in this embodiment when blade tilting operations are carried out, the right and left braces 34 and 36 are free to rotate in respectively opposite directions about the axes of pins 16 thereby to avoid compression of the right and left struts 19 and 20. Because of the link 26, however, the right and left braces 34 and 35 cannot be rotated in the same direction and therefore will transmit forces applied externally to the blade in a lateral direction to the struts 19 and 20. Also it will be noted that the offset disposition of the ends 24 and 25 on the braces 34 and 35 together with their connection by the link 26 will facilitate a measure of axial freedom between the braces 34 and 35 in the same manner as the embodiment of FIGS. 1-4. Moreover, the pins 27 and 28 interconnecting the ends of the link 26 with the braces 34 and 35 are provided with a measure of play by which the 4 degree of relative rotation between the braces 34 and 35 plrovided by the sleves 17 in FIGS. l-4 will be accommoated.

In the alternative embodiment shown in FIGS. 7 through 9 of the drawings, the braces 34 and 35 are again connected by the joint generally designated 17 which in these embodiments includes a member 29 or 30 movable axially 0f the braces 34 and 35 and is internally received in an appropriately shaped inner end of the brace 34. In both instances, relative rotation about a perpendicular axis 31 is provided.

Referring specifically to the embodiment of FIG. 7, the internal end portion of the brace 35 is formed as a balljoint 32 receivable in a bush 29 inserted into an axial bore provided on the inner end of the brace 34. The bush 29 is slidable within the bore 36 thereby to provide free relative movement between the ends of the braces 34 and 35.

In the embodiment of FIGS. 8 and 9, the inner end portion of the brace 35 is formed as a shaft 37 of uniform diameter received slidably within a member 30 secured rotatably by a pin 38 in a yoke-like end portion 39 on the inner end of the brace 34. Hence here, again, transmission of stress between the pin 16 supporting the respective braces 34 and 35 on the bracket 33 is avoided.

Thus it will be appreciated that by this invention an improved tiltable dozer blade mounting assembly is provided by which externally initiated lateral forces imposed on the dozer blade may be absorbed by the mounting but in a way so that tilting movement of the blade in uninhibited. Although several preferred alternative embodiments of the invention have been illustrated and described, it is contemplated that further variations in the specific embodiments described and illustrated herein will become apparent to those skilled in the art. Accordingly, it is expressly intended that the foregoing description is illustrative of preferred embodiments only, not limiting, and that the true spirit and scope of the present invention will be determined by reference to the appended claims.

I claim:

1. In a tilting dozer blade mounting assembly haying a pair of lateral load resisting struts extending outwardly and rearwardly of the dozer blade, means for connecting said struts to the blade comprising: a pair of brace members, bracket means or connecting said brace members in generally aligned end to end relation parallel to the lateral extent of the blade, said bracket means including laterally spaced vertical pins pivotally engaging the brace members respectively, means to connect the outer ends of said brace members respectively to said struts, and yieldable means connecting the inner ends of said brace members, said yieldable means including a ball member formed on the end of one of said brace members and a slidable socket bush received in an axial bore in the inner end of the other said brace members, said ball member being connected within said socket bush, whereby the transmission of both longitudinal and torsional stress between said brace members is prevented.

2. In a tilting dozer blade mounting assembly having a pair of lateral load resisting struts extending outwardly and rearwardly of the dozer blade, means for connecting said struts to the blade comprising: a pair of brace members, bracket means for connecting said brace members in generally aligned end to end relation parallel to the lateral extent of the blade, said bracket means including laterally spaced vertical pins pivotally engaging the brace members respectively, means to connect the outer end of said brace members respectively to said struts, and yieldable means connecting the inner ends of said brace members, said yieldable means including a yoke portion on the inner end of one of said brace members, a pivoted member supported by said yoke for rotation about a vertical axis, said yoke being formed with a radial bore therethrough, the other of said brace members having a shaft extension on its inner end slidably and rotationably received in said bore, whereby the transmission of longitudinal and torsional stresses between said braces is prevented.

References Cited UNITED STATES PATENTS 6 3,395,74 8/1968 Wiet 172803 3,503,457 3/1970 Smith et a1 172803 ROBERT E. PULFREY, Primary Examiner 5 S. C. PELLEGRINO, Assistant Examiner 

